Goals for the coming year: (1) To continue our long term studies of the genetic and immunologic factors influencing inducibility of B cell lymphomas. Specifically, 2a4b/new, which has been freshly rederived from a cross of B10.A and B10.129(21M) mice will be tested, to determine whether the particular combination of H-2a with H-4b is responsible for susceptibiliy. Similarly, strains of mice of genotypes H-2b, H-4b and H-2a, H-4a derived from our original 2a4b crossed to C57BL/10 will be tested. (2) We will attempt to elucidate the mechanism by which specific passive immunotherapy with A-Id cures established B cell lymphomas and identify the host component which we have shown to be involved. (3) We will extend our studies of A-Id to B cell lymphomas other than CH1 as these become available.